Effective electron-electron and electron-phonon interactions in the Hubbard-Holstein model
Abstract
We investigate the interplay between the electron-electron and the electron-phonon interaction in the Hubbard-Holstein model. We implement the flow-equation method to investigate within this model the effect of correlation on the electron-phonon effective coupling and, conversely, the effect of phonons in the effective electron-electron interaction. Using this technique we obtain analytical momentum-dependent expressions for the effective couplings and we study their behavior for different physical regimes. In agreement with other works on this subject, we find that the electron-electron attraction mediated by phonons in the presence of Hubbard repulsion is peaked at low transferred momenta. The role of the characteristic energies involved is also analyzed.
Cite
@article{arxiv.cond-mat/0601374,
title = {Effective electron-electron and electron-phonon interactions in the Hubbard-Holstein model},
author = {G. Aprea and C. Di Castro and M. Grilli and J. Lorenzana},
journal= {arXiv preprint arXiv:cond-mat/0601374},
year = {2009}
}
Comments
23 pages, 5 figures